GWT compile error: Rebind result cannot be abstract DOMUtilImpl

Question

I am using GWT 2.8.1 and getting this error while compiling.

Errors in 'com/allen_sauer/gwt/dnd/client/util/DOMUtil.java'
     [java]       [ERROR] Line 39: Rebind result 'com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImpl' cannot be abstract

I tried adding this in my module but it didn't worked.

   <replace-with

class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImplOpera">
        <when-type-is 
class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImpl" />
        <when-property-is name="user.agent" value="opera" />
    </replace-with>

    <replace-with

class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImplSafari">
        <when-type-is 
class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImpl" />
        <when-property-is name="user.agent" value="safari" />
    </replace-with>

    <replace-with 
class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImplIE6">
        <when-type-is 
class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImpl" />
        <when-property-is name="user.agent" value="ie6" />
    </replace-with>

    <replace-with

class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImplMozilla">
        <when-type-is 
class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImpl" />
        <when-property-is name="user.agent" value="gecko1_8" />
    </replace-with>

    <replace-with

class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImplMozillaOld">
        <when-type-is 
class="com.allen_sauer.gwt.dnd.client.util.impl.DOMUtilImpl" />
        <when-property-is name="user.agent" value="gecko" />
    </replace-with>

My GWT-dnd version is 3.2.3

Please help me in fixing